The invention relates to use of ultrasonic radiation at relatively low levels into living tissue, as for the non-invasive healing treatment of bone fractures, pseudarthroses and the like.
Duarte U.S. Pat. No. 4,530,360 describes a technique of bone defects of the character indicated using a pulsed radio-frequency ultrasonic signal applied via a transducer to the skin of a patient and directed to the site of the defect. The radio-frequency signal is in the range of 1.3 to 2 MHz, and it consists of pulses at a repetition rate of 100 to 1,000 Hz, with each pulse having a duration in the range 10 to 2,000 microseconds. The Duarte apparatus comprises a radio-frequency oscillator connected to a driver, and a pulse generator is arranged to control driver output in accordance with a preselected duration and repetition rate of bursts of radio-frequency oscillations in the driver output. A flexible radio-frequency cable connects driver output to a body applicator, in the form of a hand-held plastic tube, one end of which is closed to mount a piezoelectric transducer, in the form of a thin flat disc, excited for thickness resonance.
Necessarily, therefore, in the Duarte apparatus, the source of electrical energy is remote, as on a table top, and the flexible connection to the body applicator must, in use, always be electrically "live" and, therefore potentially hazardous. Also, for the power levels involved, and considering the fact that two or more transducers seldom can be found to resonate at precisely the same frequency, the radio-frequency must be pretuned to serve one and only one transducer. In other words, apparatus of the Duarte patent necessarily dedicates the remote signal-generating part of the system to the particular applicator. And any attempt to replace a damaged applicator must involve a returning of the signal-generator to the newly substituted applicator. Said application Ser. No. 247,105 is primarily addressed to these problems.
Said application Ser. No. 628,403 is primarily concerned with improved means of flexibly mounting the ultrasonic transducer in apparatus of the character indicated. And the present application addresses various problem aspects of selectively and removably positioning the ultrasonic transducer, particularly in situations wherein, for intervals between therapeutic ultrasonic applications, little or no apparatus, such as a cast, can be tolerated on the body part requiring treatment.
Ultrasonic therapy of the character indicated is found to accelerate natural bone-repair processes of animals, as well as human beings, and the present application particularly address problems of providing such therapy to horses, such as race horses that have sustained bone damage which might otherwise require prolonged side-lining rest and rehabilitation. It is to be understood, however, that much of what is herein described for equine application is also applicable to other animals and to human beings.